Plate inverting mechanism



4 Sheets-Sheet 1 Filed NOV. 27, 1964 INVENTOR HEINZ F. CARLSON BY /W.

ATTORNEY Se t. 27, 1966 H. F. CARLSON 3,

PLATE INVERTING MECHANISM Filed Nov. 27, 1964 4 Sheets-Sheet 2 Sept. 27, 1966 H. F. CARLSON 3,275,122

PLATE INVERTING MECHANISM Filed Nov. 27, 1964 4 SheetsSheet 5 INVENTOR HEI NZ F. OARLSON ATTORNEY United States Patent 3,275,122 PLATE INVERTING MECHANISM Heinz F. Carlson, Santa Clara, Calif., assignor to FMC Corporation, a corporation of Delaware Filed Nov. 27, 1964, Ser. No. 414,234 10 Claims. (Cl. 198-33) The present invention pertains to dishwashing apparatus, and more specifically relates to a machine for orienting dinner plates prior to their being loaded into an automatic dishwashing machine. I

One type of institutional dishwashing installation requires that the plates to be washed are oriented to inverted positions before being conveyed into the dishwashing machine. Soiled plates are deposited directly upon the delivery or feed conveyor for thedishwasher in random upright or inverted positions. The plate orienting mechanism of the present invention is cooperatively associated with the feed conveyor, and intercepts and inverts the initially upright plates, but does not change the orientation of those plates which are already inverted.

One of the objects of the present invention is to provide a plate inverting mechanism which is capable of intercepting and inverting only the upright plates of a continuously moving lane of plates in random upright and inverted positions. The plate inversion is helpful because loosened substances on the upper sides of the plates clear the plates with the assistance of the force of gravity.

Another object is to provide plate inverting mechanism which is rapid in operation, yet minimizes damage to the plates.

Another object is to provide a plate inverting mechanism which is a self-contained unit requiring no mechanical or other connections to the machines from which it receives and to which it discharges the plates.

Another object is the provision of dishware orienting mechanism which requires only a predetermined minimum spacing of the dishware supplied thereto and is operable at any spacing exceeding that minimum.

Other objects and advantages of the present invention will become apparent from the following detailed description of the invention taken with the accompanying drawings, wherein:

FIGURE 1 is a schematic plan of the plate orienting mechanism.

FIGURE 2 is an enlarged vertical section, partly in elevation, taken along lines 22 on FIGURE 1.

FIGURE 3 is a schematic control diagram.

FIGURE 4 is an enlarged transverse section taken along lines 44 on FIGURE 1.

FIGURE 5 is a section similar to FIGURE 4 and illustrates the apparatus in conjunction with an inverted plate.

FIGURE 6 is a section similar to FIGURE 2, but in a different operational position.

FIGURE 7 is a schematic perspective illustrating a modified form of the present invention.

FIGURE 8 is an enlarged section of the area indicated by the arrow 8 on FIGURE 7.

FIGURES 9-12 are schematic elevations illustrating successive operational steps in the inverting operation carried out upon an initially upright plate by the mechanism shown in FIGURE 7.

The plate inverting orienting mechanism 10 (FIG. 1) is positioned at the inlet end of dishwashing apparatus, not shown, and includes a support frame 12 having an elongate belt support plate 14 on its upper end. The upper flight 16 of a flexible conveyor belt 18 is slidable over the plate 14 in the direction of the arrow 20. Conveyor belt 18 is continuously driven by a conventional motor 3,275,122 Patented Sept. 27, 1966 ice and drive train (not shown), and has a rough outer surface so as to positively convey the plates without slippage. At .some upstream point, other apparatus, which is not a part of the present invention, deposits soiled dinner plates 22 upon the belt flight 16 in spaced upright or inverted positions. Due to the requirements of the dishwashing apparatus to which the plates are fed, all initially upright plates must be inverted, for the reasons described, and the initially inverted plates must remain inverted.

An angle bar guide 24 (FIGS. 2 and 4) having an upright flange 26 is positioned at each side of the upper belt flight 16 to restrain both the upright and inverted plates 22 from lateral movement so that they are carried by the belt fight 16 in a substantially linear path through an inverting station 28. As shown in FIGURES 1 and 2, each flange 26 is provided with a notch 30 that accommodates the corresponding channel bar legs 32 and 33 of a U-shaped plate gripper 34. The channels 32 and 33 are interconnected by a base channel 36 which extends across the conveyor flight 16 and has each end secured to a pivotable drive arm 38; all channels lie in a common plane and their open sides faces the incoming plates when the plate gripper 34 is in receiving position.

The channels 32 and 33 are each supported in a downwardly limited adjusted position by an associated stop bolt 40 which is aligned with the drive arm 38 and is threaded upwardly through a metal platform 42. The platform 42 underlies the inverting station 28 and supports the support plate 14 for the belt flight 16. The interspacing of the channels 32 and 33 (FIG. 4) and the spacing of the channels 32, 33 and 36 above the conveyor flight 16 is such that the rim portion 44 of each upright plate 22 slides into the open sides of the channels.

Mounted in the central portion of the base channel 36 is a plate sensor comprising a normally open electric switch 46 that has an actuator 48 which is positioned to be depressed by the leading portion of the rim of an upright plate positioned in the plate gripper 34. As will be presently described, closure of the switch 46 causes the plate gripper 34 to pivot about 180 degrees, invert the plate it grips and deposit the inverted plate on the upper belt flight 16 at a downstream location.

The drive arms 38 (FIG. 1) are each secured to a hub 50 which is in turn secured to an associated stub shaft 52. The two stub shafts 52 are in axial alignment and are supported in associated bearings 54 that are mounted atop the platform 42 and straddle the conveyor flight 16. One stub shaft 52 is provided with a counterbalance arm and weight 55 which lies in the same plane as the U-shaped gripper 34 in order to offset the weight of the gripper and a plate held thereby. However, the counterbalance force is not suflicient to lift the channels 32 and 33 oif the stop bolts 40 if the plate gripper 34 is not engaged with a plate.

The other stub shaft 52 has a chain and sprocket drive connection 56 to the output shaft 58 of an air-operated power unit 60. The drive connection includes a driven sprocket 57 (FIG. 2) and a driving sprocket 59, which sprockets are respectively secured to the shafts 52 and 58. Power unit 60 is preferablp a mechanism of the type manufactured by Graham Engineering of Palo Alto, California and designated as a ROTA-CYL, Model 15A, The inner mechanism of thepower unit comprises a double-acting piston which is connected to a chain trained over a sprocket on the output shaft 58. When the piston is energized to move in one direction by air under pressure, the sprocket and chain turn the shaft 58 for 90 degrees clockwise from its FIGURE 2 position. Reverse actuation of the piston then returns the shaft 58 to its initial position.

The ratio of angular movement of the driving sprocket 59 to the driven sprocket 57 is 1:2. The sprocket 57 is a lost-motion connection to the hub 57a of the sprocket 57 so that its angular extent of possible movement is a more than 180 degrees in order that the plate gripper 34 can decline toward the conveying flight in its plate discharge position. 62 (FIG. 2) which is secured to the stub shaft 52-and Such connection comprises a driving pin.

is engaged in. a circumferentially enlarged slot 64 in the hub 57a of the sprocket 57. The relation'of the driving 7 pin 62 to the walls defining the slot 64 is such that at the time the power unit 60. is energized after a plate closes the switch 46, as shown in FIGURE 2, the sprocket hub 57a will immediately move the driving pin 62 and thus begin to pivot the plate gripper 34 about'the axes of the stub shafts 52.

Accordingly, when the. plate gripper 34 (FIG. 6) is' driven for 180 degrees and reaches a horizontal plane parallelto the belt flight 16 at the downstream limit of its powered stroke, the clearance 'between the, pin 62.

and the slot 64 allows gravity to lower the plate gripper 34 about 10 degrees further so that the free portion of the plate rim 44 rests upon the conveying flight 16. The

'conveying flight 16 thus pulls the inverted plate out of the plate gripper 34.

The switch 46 is associatedwith a control circuit 65 (FIG. 3) which includes a spring-return air valve 66 that is operated by a solenoid 68. The contacts of the switch 46 are in series connection with a control relay CR between power input lines Ll and L2. Aholding circuit is provided to maintain the plate gripper 34 in its discharge position until the plate has been removed.

The holding circuit includes normally open contacts CR1 of relay CR, and a normally closed switch 70 (FIGS. 1 and 3) in series connection with the contacts CR1 and in bypassing relation to the switch 46. Switch 70,has an upstanding actuator 71 (FIGS. 1 and 2) which lies in the path of the plates discharged from the plate gripper 34 sothat the contacts of the switch 70 open each time a plate is conveyed therepast.

The power inputline L1 isconnected to one terminal of the solenoid 68, and the other solenoid terminal is connected to the power input line'L2 through normally open relay contacts CR2. Valve 66 is connected to an air input line 72, which in one position of the valve 66 (that position in which the solenoid 68 is de-energiz ed) conducts air through a valve passage 66a and a conduit 73 to the power unit 60. The piston of the power unit is thus at one extreme of movement corresponding to the plate receiving position of the plate gripper 34. In attaining such position from a previous actuation of the power unit 60, a conduit 74 bleeds the exhaust air through a valve passage 66b to atmosphere.

When the contacts of the switch 46 are closed by reason of the rim of a plate contacting the switch actuator 48 (FIG. 1), the controlrelay CR is energized and its,

through passage 660 with the conduit 74 and the oppo site side of the piston. Meanwhile, air expelled:by the piston is exhausted through the conduit 73 and the valve passage 66dto atmosphere. At the completion of this power, stroke, the plate gripper 34 is in its plate discharge 4 I position and must be kept in such position until the plate is completely free of the gripper.

As the plate leaves the gripper 34, the contacts of'the switch 46 open; ,the closed switch 70 and closed relay contacts CR1, however, 'maintain energization of the relay CR. Relay contacts CR2 thus remain closed and thereby maintain the valve 66 in its last described position while the plate moves to the phantom-line position shown in FIGURE 1 and depresses the switch actuator 71. opened, and the control relay CR is de-energized. Relay contacts CR2 thereby open, and the solenoid 68 isdeenergized. A solenoid return spring 76 is then .free to return the valve to its former position, at which time the power unit shaft 58 is energized in a reverse direction and carries the plate gripper 34 to its initial plate-receiv ing position.

It an inverted plate. approaches, the plate gripper 34 (FIG.'5) whenthe plate gripper is in its FIGURES 1 and 2 plate receiving position,;the leading portion of the wall of the plate acts as a cam or wedge which rides under, the

base channel 36 of the plate gripper 34 and bodily liftsthe plate gripper 34 until the plate, passes. downstream out ofcontact with the channel 36. This operation is made possible by the arrangement of the driving 'pin62 and the slot 64 because the plate gripper 34 can rise about 10 degrees from receiving position without rotating the driven sprocket 57. This amount of movement of the plate gripper 34 is more than sufiicient to permit passage of the inverted plates.

The modified form of plate inverter, 80 (FIG. 7) accomplishesaan inverting action upon upright plates-without any power mechanism other than that which is used to drive the plate conveying means.

a The plate inverter 80 includes a frame 82 having pairs of support legs 84 and 86, and a conveyor belt 88.: As in the case of-the conveyor belt 18, the conveyor belt 88 is provided with an outer surface 89 having a high coefli lugs 94 provide transport pockets 97 for the plates 22.

For reasons which will presently appear, the plates (deposited by any suitable means at some upstream location) only occupy every third transport pocket97. Asin the case of the plate inverting mechanism 10, the plates 22 have no uniform upright or inverted orientation.

Intermediate its ends, each pusher lug 94 (FIGS. 7 and 8) is provided with-a pair of open-end slots 96 to clear a corresponding pair of plate inverting arms 98 whlch depend from a common shaft 100 and have lower end surfaces 101 closely spaced from the conveying flight and the bottom of the slots 96.

The plate inverting arms 98 are secured-to the shaft in alignment with one another, and the shaft is rotatablymounted in'bean'ngs 102 thatare'secured to the upper ends of the legs 86. A stop arm'104 is fixed to one outwardly projecting end of the. shaft 100 and abuts a stop block 106 that thus limits swinging movement ofthe plate inverting arms 98 upstream beyond a position in which the arms are substantially, vertical.

The arms 98 are urged toward this latter position by a tension spring 110 that interconnects thefree end of the stop arm 104 anda fixed pin on the adjacentleg 86.

The lower end of each plate inverting arm 98 (FIG. 8)

is provided with a footor hook portion 112,,the function of which is to engage the, undersurface of the leading portion of the rim ,44 of each upright plate 22. Thus, the upper edge of each hook 112 conforms in profile The normally closed contacts of switch 70 are thus:

5 to the plate rim 44 and the adjacent outer wall surface 114 of the plate.

In operation, the soiled plates 22 are placed either upright or inverted upon the upper conveying flight 90 in every third pocket 97. In the case of an upright plate approaching the inverting arms 98, as shown in FIGURES 7-9, the leading portion of the plate rim 44 attains a position overlying the hook 112. As illustrated in FIG- URE 10, continued downstream movement of the plate thereby causes the inverting arms 98 to pivot upward as the trailing pusher lug 94 propels the plate. Because the tension spring 110 urges the pivotable arms 98 downward, and because the hooks 112 straddle the centerline of the plate, the hooks remain engaged with the plate and the leading end of the plate rises from the conveyor flight 90 as the arms 98 pivot about the axis of their support shaft 100.

'As shown in FIGURE 11 when the plate is nearly vertical, the arms 98 are below horizontal. In this way the upper sector of the plate is rapidly pushed downward by the force of the spring 110 soon after the plate inclines rearward beyond vertical, whereby the inverted plate tips into the following empty pocket 97 (FIG. 12). Because the next following pocket 97 is empty, the hooks 112 have sufiicient time to snap into their initial position in front of the next incoming plate.

If a plate is already in the desired inverted position, the arms 98 are merely pushed downstream by the plate until the hooks 112 ride off the rear portion of the plate. The spring 110 then returns the arms 98 to vertical positions in readiness for either passing or inverting the succeeding plate according to its orientation.

From the foregoing description, it will be apparent that the plate inverting mechanisms herein disclosed provide simple structures which will handle, with obvious dimensional changes, all sizes of round dishware having rim portions larger than the base portions.

While particular embodiments of the invention have been herein shown and described, it will be apparent that the various modifications may be made without departing from the spirit of the invention, and that the scope of the invention is limited only by the scope of the claims appended hereto.

Having thus described the invention, that which is believed to be new, and for which protection by Letters Patent is desired, is:

1. Plate inverting apparatus comprising a continuously driven conveyor arranged to convey from upstream to downstream positions a lane of plates lying in random upright and inverted positions, a plate gripper mounted over said conveyor, means mounting said plate gripper for movement :between a receiving position in which said conveyor moves the leading upright one of said plates into supported relation with said plate gripper, an intermediate position wherein the supported plate is out of engagement with said conveyor, and a discharge position in which the initially upright plate is inverted and its downstream rim portion lies on said conveyor, means carried by said plate gripper for slidably receiving the laterally opposed rim portions of said leading plate for movement of the plate with said gripper, power means for efiecting movement of said gripper from said receiving position to said discharge position, and means for sensing the presence of a plate supportingly engaged by said plate gripper in said receiving position and operative to energize said power means for movement of said gripper to said discharge position.

2. Plate inverting apparatus according to claim 1, wherein a lost motion drive connection is provided between said plate gripper and said power means, said plate gripper in said receiving position lying in the plane of the rim of upright plates, said power means effecting 180 degree movement of said gripper above said conveyor toward said discharge position, said lost motion drive con- 6 nection thereafter accommodating gravitation of said gripper toward said conveyor until the downstream rim portion of the plate carried by said gripper contacts said conveyor.

3. Plate inverting apparatus according to claim 2, and further including means for maintaining the initial direction of energization of said power means, until the plate is carried out of said plate gripper by said conveyor.

4. Plate inverting apparatus according to claim 1, in which said plate gripper is formed of U-shaped inwardly open channels adapted to slidably receive the rim portions of incoming upright plates when said gripper is in said receiving position.

5. A plate inverting apparatus according to claim 4, in which said plate sensing means is a switch mounted on said gripper and having an actuator lying in the path of an incoming upright plate.

6. Plate inverting apparatus according to claim 4, in which said plate gripper is provided with means defining a pivot axis extending transversely over said conveyor and spaced downstream from said gripper when said gripper is in said receiving position.

7. Plate inverting apparatus as defined in claim 6, and further including a counterweight connected to and lying in the plane of said gripper at the opposite side of said pivot axis.

8. Plate inverting apparatus comprising a continuously driven elongate conveyor having an upper flight arranged to convey from upstream to downstream positions a lane of plates lying flat on the conveying surface in random upright and inverted positions, a plate gripper overlying said conveying surface, means defining a pivot axis for said plate gripper, said pivot axis being transversely related to the longitudinal dimension of said conveying surface a and said gripper being pivotable about said axis between a plate receiving position in which the plate gripper extends in an upstream direction from said pivot axis and a plate discharging position in which the plate gripper extends in a downstream direction from said pivot axis, said plate gripper being substantially parallel to said conveying surface in said plate receiving position and adapted to slidably receive rim portions of upright plates, power means for moving said gripper between said receiving and discharging positions, and plate sensing means connected to said power means and carried by said plate gripper for sensing a plate engaged therewith, said sensing means governing said power means to cause said plate gripper when engaged with an initially upright plate to pivot to said discharging position ,and thus invert the plate.

9. Plate inverting apparatus comprising a conveying flight arranged to convey from upstream to downstream positions a single file of plates lying in random upright and inverted positions; a plate gripper mounted over said conveyor, said gripper comprising a U-shaped frame formed of inwardly open channels adapted to slidably receive the corresponding rim portions of upright plates, said gripper being pivotable from a plate receiving position wherein the channels lie in the plane of the rims of upright plates to an inverted discharge position removed from said plate receiving position in a downstream direction; pivot means mounting said gripper for pivotal movement between said receiving and discharge positions about an axis extending transversely over said conveyor; power means for driving said gripper between said receiving and discharge positions; plate sensing means carried by said gripper for sensing the presence of a plate supportingly engaged therewith; and control means governed by said sensing means and connected to said power means for driving said gripper between said receiving and discharge positions in accordance with the presence or absence of a plate engaged with said gripper.

V 10. Plate inverting apparatus comprising a driven conveyor having an upper conveying flight for transporting a single file of spaced apart inverted and upright plates, at

shaft rotatably mounted above said conveyor, andtan inverting arm depending from said shaft in alignment with the notches in said pusher lugs and having a distal end foot portion spaced from said conveying flight in position to be straddled by the notched portion of each passing pusher lug, said foot portion extending in an upstream direction and having an upper surface conforming to the undersurface of the plate rim of an upright plate, the distance between the axis of said pivot shaft and the upper surface of said foot being greater than the diameter of the plates whereby antupright plate is transported by said conveyor into a position wherein the leading rim portion overlies said foot and is elevated from the: conveyorflight',

due to upward swinging movement of the'foot, to' and beyond a vertical. position so that the plate is tover'balanced and falls rearwardly into the succeeding pocket in an inverted position.

References Cited by the Examiner UNITED STATES PATENTS 1,462,468 7/1923 Schaller. 2,277,940 3/1942 W001. 7 2,699,246 1/1955 Harrison et'al 198-33 X 3,074,530 1/1963 Rosenleaf 198-33 3,206,001 9/1965 ,Peppler 198168 X EVON C. BLUNK, Primary Examiner.

R. E. KRISHER, Assistant Examiner. 

1. PLATE INVERTING APPARATUS COMPRISING A CONTINUOUSLY DRIVEN CONVEYOR ARRANGED TO CONVEY FROM UPSTREAM TO DOWNSTREAM POSITIONS A LAND TO PLATES LYING IN RANDOM UPRIGHT AND INVERTED POSTIONS, A PLATE GRIPPER MOUNTED OVER SAID CONVEYOR, MEANS MOUNTING SAID PLATE GRIPPER FOR MOVEMENT BETWEEN A RECEIVING POSITION IN WHICH SAID CONVEYOR MOVES THE LEADING UPRIGHT ONE OF SAID PLATES INTO SUPPORTED RELATION WITH SAID PLATE GRIPPER, AN INTERMEDIATE POSITION WHEREIN THE SUPPORTED PLATE IS OUT OF ENGAGEMENT WITH SAID CONVEYOR, AND A DISCHARGE POSITION IN WHICH THE INTIALLY UPRIGHT PLATE IS INVERTED AND ITS DOWNSTREAM RIM PORTION LIES ON SAID CONVEYOR, MEANS CARRIED BY SAID PLATE GRIPPER FOR SLIDABLY RECEIVING THE LATERALLY OPPOSED RIM PORTIONS OF SAID LEADING PLATE FOR MOVEMENT OF THE PLATE WITH SAID GRIPPER, POWER MEANS FOR EFFECTING MOVEMENT OF SAID GRIPPER FROM SAID RECEIVING POSITION TO SAID DISCHARGE POSITION, AND MEANS FOR SENSING THE PRESENCE OF A PLATE SUPPORTINGLY ENGAGED BY SAID PLATE GRIPPER IN SAID RECEIVING POSITION AND OPERATIVE TO ENERGIZE SAID POWER MEANS FOR MOVEMENT OF SAID GRIPPER TO SAID DISCHARGE POSITION. 